RT1064 freertos lwip udp example receive from broadcast

[akift]

Hi,

I am working on RT1064EVK and using I evkmimxrt1064_lwip_ipv4_ipv6_echo_freertos example.

udp echo example receives the data which send to device IP only.

But I would like to receive the broadcast data - which send to any IP-  and specific port.

What modifications I need to do in the example code?

I may need to add below lwipopts.h.

#define IP_SOF_BROADCAST 1
#define IP_SOF_BROADCAST_RECV 1
#define LWIP_BROADCAST_PING 1

And after I need to change binding address to IP_ADDR_ANY.
But I couldn't find where to change.

Any help would be appreciated. Thanks

[jaylarson]

Hi @akift,

I'm not sure @kerryzhou understood your question. 

I have managed to receive broadcasts using code like the following snippet:

	struct netconn *pListenerConnection = netconn_new(NETCONN_UDP);
	if (!pListenerConnection)
	{
		// failed to listen
		DebugPrintf("listener failed on netconn_new()\n");
		goto restart;
	}

	struct netbuf *pBuf;
	lastNetError = netconn_bind(pListenerConnection, IP_ADDR_ANY, listenPort);
	if (ERR_OK != lastNetError)
	{
		// failed to listen
		DebugPrintf("Listener failed on netconn_bind(), return %i\n", lastNetError);
		netconn_delete(pListenerConnection);
		goto restart;
	}

	// process requests from possible clients.
	while (1)
	{
		lastNetError = netconn_recv(pListenerConnection, &pBuf);

		// depending on the return
		if (ERR_OK != lastNetError)
		{
			// some error.
			DebugPrintf("listener got error %i in netconn_recv()\n", lastNetError);
			// restart the connection
			netconn_delete(pListenerConnection);
			goto restart;
		};
		// pBuf has the message:  
		uint8_t packet[8];  // just interested in the first this many bytes
		size_t packetSize = netbuf_copy(pBuf, packet, sizeof(packet));

		if (packetSize != sizeof(packet))
		{
			DebugPrintf("listener got an unexpected request, not %d bytes long.\n", packetSize);
			// delete the pBuf and wait for another UDP packet.
			netbuf_delete(pBuf);
			continue;
		}
      // use the data in packet.

		netbuf_delete(pBuf);
	}

 I hope it helps.

Cheers,

[kerryzhou]

Hi @akift ，

  This post also useful to you:

https://blog.csdn.net/m0_61659911/article/details/132415649

Wish it helps you!

Best Regards,

Kerry

[kerryzhou]

Hi @akift ,

  Thanks for your interest in the NXP MIMXRT product, I would like to provide service for you.

  I don't have the broadcast demo, but I write a multicast demo previously.

  I think, you also can refer to my multicast doc, I also share one document, but just write in Chinese, the doc contains the code and test result picture.

  If you still have question about it, please kindly let me know.

Best Regards,

Kerry

[akift]

Hi @kerryzhou,

Thank you but your reply is not helpful. Also the implementations are very different than NXP example.

When I scrutinize the information in the two examples, I can only conclude that LWIP_IGMP is not defined.

I have defined #define LWIP_IGMP 1 in lwipopts.h , but still I can't receive broadcast data.

Could you have a look evkmimxrt1064_lwip_ipv4_ipv6_echo_freertos example in the SDK?

The example is provided by NXP, so I assume you or your colleagues  can help us very easily. Probably a small change is needed to receive broadcast data over udp. 
I have tried the change mentioned in the first post but it is not working. There might be a bug in the example.

Thanks

[kerryzhou]

Hi @akift ，

  My example is the multicast, not the broadcast.

 To the broadcast, do you try this code:

You can try it again.

Wish it helps you!

If you still have question about it, please kindly let me know.

Best Regards,

Kerry